How and where to make/put a log Pile?

I want to encourage insects into the garden. Do I put the logs in a pile in shade or sun. Do I leave them be until they rot down? Is there anything else I could do. I am letting nettles develope.

 

I think the logs need to rot down slowly, so in the shade would probably be best, so that they stay damp most of the year.

 

Thanks